Civilian ICS (Inter Communication Systems) are designed to be compatible with high impedance headsets with amplified microphones. Military ICS Systems are configured to accept low impedance headsets with unamplified microphones....
HI to LOW IMPEDANCE ADAPTER/Mates civilian headset (amp'd mic and 300 ohm earphones in parallel) to military ICS (5 ohm dynamic mic input and 10 ohm phones output), under panel...